An OSCAL Metaschema defines the the information structures that define an OSCAL model in a format-neutral form. Documentation about the meaning (semantics) and use of a given metaschema structure is provided on the Metaschema [website].
OSCAL Metaschemas are used to generate other OSCAL artifacts based on the metaschema description. These artifacts include:
- XML and JSON schemas, or data models, which are derived from the Metaschema modules and expressed as XSD and JSON Schema;
- Conversion scripts that can convert OSCAL content between the XML and JSON OSCAL formats, ensuring the resulting content is schema valid;
- XML and JSON model documentation for use on the OSCAL website.
Use of Metaschema modules in OSCAL allows us to maintain seamless and consistent support for multiple OSCAL model formats, including XML and JSON. More information is at the Metaschema Information Modeling Framework documentation site.